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How to change gravity vector as a function of time?

In some cases (e.g. fuel tank sloshing) one might need to change thegravity vector as a function of time. Furthermore, one might want to providethe time variation of the gravity vector through a text file that contains4 columns of numbers, the first being time and the other three beingthe xyz components of the gravity vector at that time instant.

Use the following scheme file. See the comments at the top of the scheme filefor usage directions.

--------Cut below this line and save in a text file entitled gravity-table.scm--------------------;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; Scheme file for use with Fluent6.0;;;; Developed By:;; Sandeep Sovani;; Technical Support Engineer;; Fluent Inc, 220 E Huron St, Ann Arbor MI 48197;; sds@fluent.com;;;; November 14th, 2002;;;; If there are any questions about the use of this scheme;; file please contact your support engineer;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;; BASIC NOTES:;;; The purpose of this scheme file is to allow the user to;;; change the gravity vector as a function of time.;;; The user specifies the x, y, z components of the gravity;;; vector at different times in a ASCII text file having the;;; following format:

;;; First line of the file should contain an integer that;;; indicated the total number of samples in the file.;;; Each of the subsequent lines should have four numbers;;; on it representing time, gx, gy, gz (where gx is the;;; x component of the gravity vector at that time, etc.)

;;; 4) Type the following command in the TUI (including the brackets):;;; (readfile "input.txt");;; where input.txt is the name of the input ascii file holding the;;; the gravity vector table

;;; 5) Under Solve->Execute Commands in the GUI, select 1 command.;;; Select it to be executed once every timestep;;; Type the following command in the command panel (including the brackets):;;; (accelerate)

;;; ADDITIONAL NOTES:

;;; If the flow time is lesser than that on the first row of the input file,;;; the gravity vector will be set to the values specified on the first row

;;; If the flow time is greater than that on the last row of the input file,;;; the gravity vector will be set to the values specified on the last row

;;; If the flow time falls between any two time values on two subsequent;;; rows of the input file, then the gravity vector components will interpolated;;; to the flow time.